The Nigerian moved to the Reds on a season-long loan deal earlier this month along with defenders Mamadou Sakho and Tiago Ilori, and Carragher feels that Moses's arrival will improve the Premier League leaders.
"Moses will be an important signing," Carragher told Sky Sports News.
"It's an area that they have struggled in maybe at times this season, in the second half being able to get out on the counter attack.
"He will give them strength in the wide areas. We've seen other clubs scrambling around on deadline day so from Liverpool's point of view it was a good thing they were done [before the deadline]."
"We'll see if [any of the signings] feature on Monday night (against Swansea City) and see if they can stay top of the table."
Liverpool have won all three of their league games 1-0 so far this season.